1. Field of the Invention
The invention relates to the fields of flow detection, measurement and control. The invention also relates to fire suppression systems, and, in particular, to multi-purpose piping systems for fire protection in structures and flow elements related thereto.
2. Description of the Prior Art
Practically any system where fluid flows in a conduit may use flow measurement devices. There are as many different kinds of flow measurement devices as there are systems where fluids flow in a conduit (such as a typical round pipe). For example, it is well known that there is a pressure drop across an orifice plate, and that this pressure drop can be used to determine the fluid flow through the pipe. The pressure drop is proportional to the velocity of the fluid in the pipe. As another example, a positive displacement device may be placed in a conduit, which directly measures the volume of fluid flowing there through. From the known volume measured by the positive displacement device, the velocity of the fluid in the pipe can be determined. Each type of flow measurement device has its strengths and weaknesses, and may be applicable to one system, while not being suitable for another.
Check valves (single and double acting) are also widely used in systems where fluids flow in conduits. The purpose of a check valve is to allow flow in one desired direction, but prevent flow in the opposite undesired direction. Existing check valves often use a moving seat, which is forced open by fluid flowing in the desired direction, but which moving seat is sealingly forced against an annular shoulder, preventing flow in the undesired, opposite direction.
It is well known to use electronic sensor means to transmit a signal generated by a flow measurement device to a read out or alarm means. The electronic output may be generated in response to a pressure transducer or the like. There are a myriad of ways to generate an electronic signal proportional to flow of a fluid in a conduit. As with our orifice plate noted above, the differential pressure is proportional to the flow in the conduit. Therefore, a differential pressure transducer exposed to the up stream and down stream fluids would produce an output electrical signal proportional to the flow of fluid through the conduit. In one type of paddle flow switch, the volume between the paddles is known, and a signal is generated indicating the number of revolutions per unit time of the paddle, thus allowing calculation of the flow velocity. Vane-type paddle flow switches are typically used in the fire protection industry, but vane-type paddle flow switches are generally not capable of measuring flow with any degree of accuracy. Gems(copyright) Sensors markets several types of flow switches in their catalogues, which switches use Reed switch technology to measure flow. These devices are equipped with a magnet which is displaced by liquid flow to actuate a hermetically-sealed Reed switch isolated within the unit body of the switch. A positive spring-return de-actuates the switch when flow decreases. The pressure drop is low since the flow sensing elements moves out of the flow path after switch actuation. With only one moving part - the shuttle, paddle, or piston - Gems Sensors"" flow switches are alleged to be inherently reliable. There are no bellows, diaphragms, or mechanical linkages to wear or get out of adjustment. Gems Sensors"" FS-200 incorporates a magnet-equipped shuttle, which is displaced by fluid flow, actuating the hermetically sealed Reed switch. Gems Sensors also provides options vane bypass, which can be opened to allow additional flow to pass through the sensor before the Reed switch is activated. This optional vane device is externally adjustable with a blade screwdriver, for simple adjustment of the amount of flow required to actuate the Reed switch. Gems Sensors"" model FS-10798 incorporates a piston which provides an alternative flow path for fluid. In the main flow path, there is a vane which can be adjusted to vary the amount of fluid flow which is required to move the piston a sufficient distance to activate the magnetic switch. The piston is equipped, of course, with a magnet, which activates an external Reed switch when it is displaced sufficiently. Therefore, there is no flow through the alternative piston path until it is displaced sufficiently to allow fluid to flow through an outlet port in the cylinder wall in which the piston moves.
It is well known to provide a dual check back-flow preventer for use in various types of systems. For example, Watts Industries, Inc, provides a Series 007 Double Check Valve Assembly. The Watts device has two moving checks in series, which are displaced by flow in a desired direction, but which positively seat to prevent flow in the undesired direction. As the checks are displaced by flow in the proper direction, flow passes out around the periphery of the checks. The checks are contained within a cage assembly, which allows passage of fluid between the legs thereof.
It is well known to provide a bypass means for allowing fluid flow around a restriction, in certain circumstances. For example, as disclosed in the Parent Applications for use in a multi-purpose piping system, it may be desirable to divert flow around a water softener where the demand for water in the residence for fire protection is greater than is able to flow through the water softener. As another example, in a chemical process, chemicals may be passed through a reactor unit. However, should the reactor become plugged or otherwise unduly restrict the flow, it may be desirable to bypass the reactor so as to prevent damage to the reactor vessel and/or a process upset. In these circumstances, it is necessary to have a bypass means which can divert flow around the flow element causing the pressure drop.
In most fluid flow systems, each of the above noted flow elements (flow measurement, check valve, bypass means) is a separate fitting which must be placed in the fluid system. It is often desirable to combine as many of the above noted functions into one device engineered for a particular purpose. The benefits of a combination of multiple devices, for example the flow meter, check valve, and means for converting a fluid flow to an electronic out put signal, are: a reduced number of devices reduces complexity, cost, and difficulty of installation of a fluid flow system.
It is also well known to provide a means for enunciating an alarm when water flows through a fire protection system. Typical commercial fire protection systems do not have significant water flow there through unless a sprinkler head is activated by a fire. Thus, the typical commercial systems need only detect whether or not flow is present, and if so, an alarm must be enunciated. That is why vane-type paddle flow switches are generally acceptable for commercial fire protection systems.
U.S. Pat. No. 6,081,196, issued to Young on Jun. 27, 2000, for Apparatus and Method for Multipurpose Residential Water Flow Fire Alarm disclosed means for using the same piping for both domestic and fire protection needs. The method provided for a flow detection and measurement means which is capable of distinguishing typical domestic flow from fire protection flow caused by the operation of one or more sprinkler heads. The ability to distinguish domestic flows from fire protection was based on the different flow regimes between fire protection and domestic uses.
The National Fire Protection Association (xe2x80x9cNFPAxe2x80x9d) has established standards for the design and operation of multi-purpose residential fire sprinkler systems. The standard is known as NFPA 13D, 1999 Ed. It defines a multi-purpose piping system (xe2x80x9cMPSxe2x80x9d) as xe2x80x9c[a] piping system within dwellings and manufactured homes intended to serve both domestic and fire protection needs.xe2x80x9d
Typical commercial fire sprinkler systems utilize a water flow detector to provide an alarm means. When a flow of sufficient, minimal, volume is detected, typical commercial systems indicate an alarm condition. The only reason that water typically flows in commercial systems is activation of a sprinkler head. Therefore, in a typical commercial system an alarm means need only determine whether or not water is flowing. Paddle flow switches are commonly used to determine when flow occurs in commercial systems. These are typically vane-type paddle flow switches.
In an MPS water regularly flows through the common piping. Flows occur to supply domestic needs within the structure. Whenever a sink, shower or toilet valve open, water flows in the MPS. Therefore, the alarm system used on typical commercial applications will not work for the MPS because simply taking a shower might cause a typical commercial flow detector to alarm when used with the MPS.
In light of this problem, typical residential and commercial applications have two completely different piping systems: (1) a fire sprinkler piping system, and (2) a domestic piping system. This doubles the number of pipes and fittings and the amount of plumbing work which has to be performed in a typical residential application. The same set of piping could not previously be used for both systems because the flow alarm could send false signals when domestic water was turned on. Alternatively, a residential application could use a fire detection system (i.e., smoke detector system). However, a smoke detection system does not alarm when water flows. Therefore, with a smoke detection system and no flow alarm, the fire sprinklers could run for days, causing extensive water damage, while the home owner is away on vacation and no alarm would sound. Also, smoke detection systems can be expensive.
As noted above, U.S. Pat. No. 6,081,196, issued Jun. 27, 2000, to Young, disclosed an Apparatus and Method for Multipurpose Residential Water Flow Fire Alarm. The apparatus for use as a multi-purpose residential fire suppression water flow alarm system disclosed in that patent was comprised of a supply side for delivering water under pressure; a multi-purpose piping system having a system side with common piping for delivering water from the supply side to a fire suppression side with one or more sprinkler heads and a domestic side for one or more domestic uses; a detecting means for detecting fire protection flow and for distinguishing that flow from a maximum domestic flow, the detecting means being disposed between the supply side and the system side; a drain test connection; and an alarm means. The method of utilizing the apparatus described above was also disclosed. One of the dependent claims from the above-noted patent claimed a detecting means comprised of an orifice plate through which water flows causing a differential pressure measured by a differential pressure switch so that the flow rate to the orifice plate is proportional to the differential pressure allowing a determination of flow rate based on the differential pressure measured.
The flow detection means could utilize any number of well known flow measurement technologies, such as U.S. Pat. Nos. 5,139,044 and 5,288,469 to Otten et al. Otten incorporates both an orifice plate and a cone-shaped plug around which the water flows. U.S. Pat. No. 5,419,203 to Carmichael discloses a device similar to the device disclosed by Otten. Otten utilizes the Hall Effect to measure the displacement of a displacement piston having a magnet incorporated therein. Carmichael utilizes strain sensors to measure the strain caused by displacement of a cone-shaped plug biased by a spring member. As the flow increases, the cone-shaped plug displaces backwardly in reaction to the flow putting greater pressure on the spring and consequently, greater pressure on the pressure sensors incorporated in the device. The Otten and Carmichael devices have several common features, namely a chamber having an orifice plate and a plug-shaped device adapted to be deflected away from the orifice plate in proportion to the flow rate through the chamber. The flow measurement means must be simple in both operation and concept so that it will be inexpensive to build and can be easily programmed and calibrated in the field. The problem with Otten and Carmichael is that their devices allow flow therethrough the instant pressure is applied across the orifice plate. As disclosed, they are not capable of serving as a bypass means for allowing flow only when the differential pressure exceeds some preset level.
Critics of the MPS have also noted that it is common for residential systems to incorporate a water softener or similar devices (such as filters, chlorination systems, UV purifiers and the like). Water softeners and similar devices can create substantial drops in system pressure and flow such that the water supply flowing through a typical residential system may not be sufficient for fire protection needs. Therefore, there is a need for a bypass mechanism which will allow sufficient flow in fire protection situations to bypass the water softener to supply the fire protection needs.
Prior art systems also suffered from problems with freezing. Where lines were in locations that could reach temperatures below freezing, it was a common problem to face freezing in the pipes, which could crack sprinkler heads and/or piping systems. Prior art systems addressed this problem in a number of ways, including dry pipe systems, which do not have any water in the piping until fire is sensed, by placing pipes in locations where they were not exposed to cold temperatures (for example, by placing insulation wrap over piping systems in favor of heated spaced below) and the like.
The NFPA allowed the MPS because, in their estimation, the cost savings associated with single systems instead of duplicate systems would cause the MPS to be installed in more homes, thus saving more lives. However, the NFPA provides no means for alarming upon a water flow condition in the MPS, which is a system where both domestic and fire protection systems use common piping.
There was previously no flow detection means for use with an MPS. As noted above, typical flow detection means alarm upon detection of a flow. Therefore, given the common piping system in an MPS, typical domestic uses could cause the prior art flow detection means to send an alarm signal to the alarm means. NFPA provided for installation of a non-water-flow-based smoke detection and alarm system for use with the MPS. These non-water-flow-based smoke detection and alarm systems are expensive, and they are not capable of detecting flow through one or more fire protection sprinklers. The inability of a smoke detection system to detect and enunciate a water flow alarm could result in extensive water damage to the property.
The parent applications (application filed Apr. 05, 2000, application Ser. No. 09/450,535 filed Nov. 30, 2000, application Ser. No. 09/483,999 filed Jan. 18, 2000, and U.S. Pat. No. 6,081,196 issued 06/27/00) disclosed the MPS with a water flow alarm. Since they envisioned the MPS, common piping carried water throughout the system. After passing through the main control valve, water passed by a pressure gauge, then through flow detection means. In combination the flow detection means and the pressure gauge allowed for determination of whether the water supply is sufficient for fire protection needs. The flow detection means was connected to an alarm means which activated upon the detection of a flow rate greater than maximum domestic flow. Methods of detecting and measuring flow and alarming upon excessive flow are illustrated, for example, in Otten, et al., U.S. Pat. No. 5,228,469. Disposed after the detection means was a drain test connection. This drain test connection served the same purpose as it did in the prior art. The drain test connection also preferably included an orifice plate with interchangeable orifice plates for simulating different flow regimes. For example, one orifice plate could simulate the operation of a single fire sprinkler while another orifice plate simulated the domestic usage. These interchangeable orifice plates could then be used to calibrate the operation of the alarm means. Common piping carried water throughout the system to both domestic and fire protection uses. Rather than having distinct fire sides and domestic sides, the Parent Applications disclosed short sections of pipe split off from the common piping which were designated as either fire side or domestic side.
The Parent Applications also disclosed a flow sensor incorporating a combination orifice flow meter/displacement magnetic flow sensor in an annular housing. The annular housing was preferably be composed of a non-magnetic, metallic material, such as aluminum. Alternatively, the annular housing could be comprised of a polymer such as CPVC or similar materials. The material of construction was not critical so long as it did not interfere with the magnetic activation of the Reed switch. The annular housing had two ends, and at each end a bushing or reducer adapted to be threadedly (or by a socket) attached thereto to allow connection of an inlet pipe at an inlet end of the annular housing and an outlet pipe at an outlet end of the annular housing. A moving orifice plate, having a front face and a back face, was adapted to be received within the annular housing. The annular housing had at least one section with a continuous diameter defined therein for receiving the moving orifice plate. The moving orifice plate had a diameter which was slightly smaller than that of the continuous diameter section of the annular housing, allowing a sliding motion therein, but preventing excess fluid to flow around a periphery of the moving orifice plate. A moving plate opening was defined at or near the center of the moving orifice plate. An orifice plate magnet flange having a diameter larger than that of the moving plate opening was disposed on a back face. Disposed substantially around and outside the flange was a circular orifice plate magnet. The moving orifice plate was biased away from the outlet end by a orifice plate spring. The orifice plate spring was contained between an interior flange shoulder near the outlet end, and the orifice plate magnet. Mounted on an exterior portion of the annular housing was a Reed switch. The Reed switch was attached to the annular housing by an adjustable attachment means. Adjustment screws held the adjustable attachment means in place and allowed it to be loosened for movement of the Reed switch for calibration of the device.
The Parent Applications also disclosed another related embodiment of the combination orifice flow meter/displacement magnetic flow sensor. This embodiment was adapted to be used in systems where a water softener or similar pressure drop causing device is present or a pressure drop is to be detected. The outlet to the water softener was on the supply side of the sensor, and the inlet from the water softener was on the system side of the sensor. A xe2x80x9cbullet rodxe2x80x9d was held in place by a bullet port within the annular housing. The bullet port was comprised of an outer annular ring held in place between an annular shoulder and a bushing, support legs projecting inwardly from the annular ring, and an inner support ring. An open port area was defined between each of the support legs. Preferably, the sum of the open port areas was at least as large as the cross sectional area of the inlet pipe connected to the sensor, thus, the pressure drop through the device was minimized. A bullet rod having a head portion with a leading end and a threaded male end adapted to be received through the inner support ring was provided. A tail portion had a threaded female end adapted to threadedly engage the male end, so that the tail portion is held in place against the inner support ring. The tail portion also had a tapered end. The tapered end faced the outlet end of the sensor. The moving orifice plate opening was sized to receive the tail portion so as to allow sliding motion of the moving orifice plate and also to minimize flow between the tail and the orifice plate. Thus, as the moving orifice plate was displaced toward the outlet end by pressure drop, substantially all of the flow was diverted through the water softener until the pressure drop created by fire flow displaced the orifice plate past the tapered end, at which point water flowed through the orifice in the orifice plate. As discussed below, preferably two Reed switches were provided, the first for a trouble alarm, and the second for enunciating the alarm means.
Another embodiment of a fire protection system incorporating the apparatus is discussed below. The water from the water supply first flows through a flow sensor passing through an inlet softener line to a water softener or similar water treatment or processing device and thence through the outlet softener line back through the flow sensor. The operation of the flow sensor will be more fully described hereinafter, but for the present time it is sufficient to say that the flow sensor typically directs water through the inlet softener line through the water softener and then back through the sensor to a first pipe section. However, whether there is an excessive water demand in the system, for example such as one caused by the operation of a fire protection sprinkler, there is a mechanism incorporated in the flow sensor which allows water to bypass the water softener increasing the flow rate through the system. The water, which is passed through the water softener, is next split, some of it passing into the cold water piping, and the rest of it passing into a second pipe section.
Thence, water from the second pipe section passes through a second flow sensor. A check valve may also be incorporated in the second pipe section. The check valve prevents back flow of water, which potentially could be stagnant from the fire protection system, to the cold water piping and/or the water softener. The second flow sensor passes water down through a water heater via an inlet heater line, and back to the sensor via an outlet heater line. Again, the second flow sensor incorporates a bypass means which allows water to bypass the water heater where there is an excessive demand. After being heated, the water passes into a multi-purpose pipe section. Attached to the multi-purpose pipe section are typical domestic uses such as a shower head and a faucet. Other uses, such as toilets, dishwashers, washing machines, and the like may also be attached to the multi-purpose pipe section. Also in communication with the multi-purpose pipe section are one or more sprinkler heads. The sprinkler heads are in communication via a passive pump and a head fitting with a multi-purpose pipe section. The operation of the passive pump in cooperation with the head fitting and the sprinkler heads will be more fully described hereinafter. However, the purpose of the passive pump is to utilize the velocity head of water flowing through the multi-purpose pipe section to circulate water to and around the sprinkler heads to minimize stagnation thereat.
From the passive pump, water is passed to a head fitting. The water passes to the head fitting from the multi-purpose pipe section via the head supply line. It is returned to the multi-purpose pipe section via the head return line. A reverse-j fitting supplies water from the head fitting to the sprinkler head. The purpose of the reverse-j fitting is to cool the water supplied to the sprinkler head to insure that the sprinkler head is not activated by the temperature of the water supplied thereto. Most sprinkler heads are set to activate at a temperature of 155xc2x0 Fahrenheit. While it is not anticipated that hot water flowing through the multi-purpose piping system will exceed that temperature (most hot water heaters have a 140xc2x0 Fahrenheit maximum temperature), the reverse-j fitting helps insure that, just in case the water does exceed that temperature, the fire sprinkler is not inadvertently activated by water passing thereto.
As shown, a thermocouple in communication with the pump controller and control wiring operates to ensure that a minimum desired temperature is maintained in the common piping. The thermocouple measures the temperature of water in the common piping. If the measured temperature drops below a pre-selected level (preferably at least 40xc2x0 Fahrenheit), the pump controller initiates the action of a pump. The measured temperature may be a water temperature in the system preferably remote from the utility room where the heater is located. Alternatively, the temperature may be an air temperature or a combination of air and water temperature measurements. The pump draws water from the common piping via a pump inlet pipe. A pump outlet pipe directs water through a check valve and a return pipe so that it is recycled through the water heater. The return pipe connects to the inlet heater line to complete the circuit. Thus, water moved by the pump through the water heater is reheated to maintain a minimum temperature in the multi-purpose pipe section.
An alternative embodiment includes a return leg supply pipe and a return leg flow sensor. The return leg supply pipe may be in communication with the first pipe section. The return leg flow sensor normally prevents any water from flowing directly from the first pipe section through the return leg supply pipe into the multi-purpose pipe section. However, when an excessive water demand is made on the multi-purpose pipe section, the pressure may drop low enough so that the return leg flow sensor (without an alarm means) allows water to pass there through directly from the first pipe section, bypassing the flow sensor and the other elements of the water heater system. Alternatively, the return leg flow sensor may draw water from the multi-purpose pipe section at a point adjacent to the outlet from the flow sensor. This creates an alternative flow path for hydraulic advantage in the design of the system.
To reiterate, one of the problems to be solved by the Parent Applications was provision of a water-flow-based means of alarming the MPS. In the past, such systems had to utilize two completely different piping systems: one for domestic uses and one for fire sprinkler system uses. Previous alarms used in these systems were designed to create an alarm condition upon the detection of a flow (commonly 8-10 gpm). As noted previously, vane-type switches are very inaccurate in determining flow rate. Typical domestic flows could have caused an alarm in a prior art system. Alternatively, prior art systems used a smoke detection and alarm system which did not have a flow detector. These systems without a flow detector risked substantial water damage to the structure if a sprinkler head activated while no one was in the home.
The Parent Applications used the principle that domestic flow rates are much lower than flow rates needed for fire protection. Using a flow detection means, it was possible to create an alarm condition only upon detection of flows which are such as created by fire protection needs. Thus, an alarm condition was not created when typical domestic uses only were detected.
Preferably, the Parent Applications also incorporated a tamper detection means on the main control valve. The tamper protection means determined whether the main control valve was closed, and if so, enunciating a trouble alarm. A pressure gauge was also preferably provided in the system.
The combination orifice flow meter/displacement magnetic flow sensor disclosed in the Parent Applications could have two normally open Reed switches disposed thereon for detecting flow as indicating by displacement of the moving orifice plate. The first Reed switch was the same as previously disclosed, and enunciates a trouble or fire alarm via the fire alarm means. Preferably, the first Reed switch also activated a system which contacts emergency response personnel, such as fire departments. In addition to the fire alarm Reed switch, a second Reed switch may be provided. The second Reed switch enunciated a first stage xe2x80x9ctrouble alarmxe2x80x9d. Preferably, the first stage trouble alarm only enunciated within the structure (i.e., emergency response personnel were not contacted). The trouble alarm was created if the domestic usage was excessive. Where the system was used with the MPS, the first stage alarm would naturally cause anyone in the residence to instinctively shut off water, for example a shower they may be taking. As another example, if a resident heard a first stage alarm, and they were washing dishes, they would most likely shut off the sink faucet. This natural reaction to the first stage alarm may reduce the water flow demand below the level where the first stage alarm enunciates, eliminating the alarm condition. The first stage Reed switch is displaced a slight distance toward the inlet of the flow sensor relative to the fire alarm Reed switch. Thus, as the moving orifice plate is displaced towards the outlet end of the flow sensor, it will first activate the first stage Reed switch, enunciating the internal first stage trouble alarm. As the orifice plate continues to be displaced towards the outlet end, it will next activate the fire alarm Reed switch, which enunciates the alarm means, preferably notifying emergency response personnel. The relative linear displacement of the fire alarm Reed switch and the trouble Reed switch was to be set in the field so that there was sufficient differential in the flow which activates the first stage alarm and the fire alarm to give residents or occupants of the structures sufficient time to shut off domestic demands before a fire alarm is created. This two-stage system also serve as a safety back up, because if one of the alarm stages fail, the other still alerted residents to the potential alarm condition.
Though the Parent Applications described the inventions therein with reference to a multi-purpose piping system, it should be understood that the system could be used with any flow-based system. Further, the flow detection means disclosed could be used with any flow system, not just fire protection systems. That is, the flow detection means are capable of detecting the flow of any fluid through a piping system. The piping system could carry hydrocarbons, solvents, or any other liquid or potentially even gaseous materials for that matter.
In operation the apparatus disclosed in the Parent Applications functioned as both a domestic water supply system and a flow detection and alarm system. Under normal conditions, the water flow rate through the flow detection means did not reach the fire suppression flow rates. When one or more sprinkler heads activated, the flow detection means detected the increased flow and sent an alarm to the alarm means. The alarm means enunciated a visible and/or audible alarm indicating the alarm condition. It is well known in the prior art to activate a telephone modem-based system for calling, for example, the fire department, upon detection of an alarm condition. See, e.g., Otten, U.S. Pat. No. 5,139,044. It was preferable to incorporate such a modem-based component in the present invention to notify the fire department and other emergency contacts should a fire alarm condition be detected. If one or more domestic cutoff valves were included in the apparatus, the flow detection means also sent a signal to activate the domestic cutoff valves, shutting off water to one or more domestic uses and providing more water for the fire sprinklers.
When the two-stage alarm system was provided, it was necessary to calibrate both the first stage trouble alarm Reed Switch and the second stage fire alarm Reed switch. The preferred method was to first calibrate the fire alarm Reed switch. The calibration was very simple. First, the drain test connection is opened to simulate fire protection needs, the connection means for the Reed switch were loosened, and it was moved towards the inlet end of the sensor until an alarm condition was created. The first stage Reed switch was then moved a slight distance further towards the inlet end. A typical domestic demand was then created by using the drain test connection or flowing water from some number of plumbing fixtures. As the flow through the drain test connection exceeds the high end of the expected domestic demand, the first stage Reed switch should be activated, activating a first stage trouble alarm. If the alarm is not activated, the first stage Reed switch is moved further towards the inlet end of the sensor.
The Parent Applications also disclosed a flow sensor which can either serve as a single or double check valve. A moving seat, in cooperation with the moving plate, provided two back-flow prevention means. When water moves through the flow sensor in the desired direction, the moving seat allows water to pass thereby, and when sufficient water flows through the sensor, the moving orifice plate is displaced so that water can pass through the orifice therein or around the periphery of the plate. When water flows in the undesired direction, the moving seat is biased to cause a sealing action of a check o-ring against a check shoulder seat. Similarly, the moving orifice plate is biased so as to create a seal between an outer seat and an outer orifice o-ring, as well as between an inner seat and an inner orifice o-ring. Thus, in combination, the moving seat and the orifice plate provide a double check. Incorporating the double check technology, a single flow sensor can serve as a flow measurement device, a double check valve, a bypass means, a flow and pressure gauge or ports, as well as creating an electronic output signal for enunciating an alarm or the like.
Also disclosed was a fire protection piping system having a water supply, a means for heating water, at least one fire protection sprinkler, a common piping means for receiving water from the supply, passing it through the heating means and delivering it to at least one fire protection sprinkler, and circulating means for circulating water through the common piping back to the heating means to maintain a specified minimum temperature in the common piping. By providing these elements, the danger of water freezing in the common piping is eliminated. In one embodiment, the circulation means comprises a pump controlled by a temperature measurement means for determining when the temperature of water in the piping drops below the minimum temperature specified. The controller engaging the pump which re-circulates the water in the piping through the heating means once the temperature drops below the desired level. At the same time, the recirculating of hot water through the system also eliminates the problem of stagnation. Preferably, at least one domestic uses is also supplied with hot water by the common piping, giving homeowners have the added benefit of instant hot water from a faucet or the like.
The flow sensors disclosed in the Parent Applications incorporate at least a single stage means for enunciating an alarm. The flow sensor may incorporate as many as three or more levels of alarm for the taking of various actions by the system upon the detection of the specified level of flow required to enunciate the alarm.
A means to compensate for pressure drops in a typical MPS was provided. More particularly, typical pressure drops include, but are not limited to, a water softener which may be placed in line in the system. Water softeners are typically used in multi-purpose systems to improve the quality of water for domestic use in the residence. In addition to water softeners, pressure drops may include filters, UV treatment of water, and the like. There are many reasons why people want to treat water coming into their homes for domestic purposes. Many of these treatment means will reduce the pressure of the water through the MPS system. Thus, there may be a need for fire protection flows to bypass these pressure drops in the system, or to at least compensate for them. Pressure drops were accommodated by providing a bypass means. In typical domestic flow situations, the entire flow of the water supply should pass through the treatment method in question, such as a water softener. However, when the system side pressure drops below a set level, a relief allows additional flows through a lower pressure drop path.
A system for providing circulation of water around fire protection sprinklers, the system comprising, common piping carrying water, which water is caused to flow at periodic intervals; a head fitting receiving a fire protection sprinkler therein and further defining a chamber therein in communication with the sprinkler; supply and return lines for supplying water to and returning water from the head fitting; and a pump means for using the velocity head created by water flowing through the common piping to pump water to the head fitting causing circulation there through as a result of and in cooperation with flow through the common piping, was disclosed. The circulation systems requires no mechanical input. That is, no pumps or motors are required for the pumping system. However, it is anticipated that in some cases it may be desirable to use a mechanical pump based on either electrical, air, or similar power means. In those cases, the pump will not rely solely on the velocity head of water flowing through the common piping.
An integrated system incorporating the above-noted elements of the invention and having a two-stage alarm for enunciating a pre-alarm, as well as a full-blown fire alarm, was disclosed. The integrated system has two detectors, the first detector enunciating a trouble alarm when a specified flow is created, and if the flow further increases, a second detector enunciating a fire alarm, which also preferably calls emergency response personnel. The first trouble alarm is audible only in the residence or structure where the system is deployed. Preferably, as noted, the second fire alarm will contact emergency personnel, possibly via a telephone modem-type connection. The integrated system also preferably incorporates a tamper switch on a valve incorporated in the system to shut off the flow thereto. The tamper switch will enunciate if water flow to the fire protection system is shut off.
It is a further object of the invention to provide a system for use in a commercial application which meets the heating/cooling needs of the structure, as well as the needs for fire protection. The integrated system uses one set of piping to provide re-circulated water for heating/cooling, as well as to provide water for fire protection purposes. A water flow alarm is provided in the system using one of several means to determine whether a fire sprinkler has been activated.
Finally was disclosed in the Parent Applications a system which can be used as a water flow monitor when a structure is unoccupied. That is, using the flow sensor apparatus in cooperation with a standard structural alarm system, it is possible to create a water flow alarm which will indicate when there is a probable leak in a structure. The structure alarms in question typically have three modes of operation: a first mode where the structure is occupied, and the alarm is not armed; a second mode where the structure is occupied, but the alarm is activated with a relatively long time delay alarm; and a third mode where the structure is unoccupied. The water monitor alarm operates with a short time delay alarm when the alarm system is in the third mode, indicating that there should be little or no water usage within the structure.
Testing of the flow sensor disclosed in the Parent Applications having a bullet rod and a moving orifice plate revealed that a large percentage (on the order of 30%) of the flow therethrough was not bypassed through the water softener or similar device. Rather, a large percentage leaked around the outer periphery of the moving orifice plate or between the bullet rod and the orifice. Such water leaking through the device reduced the percentage of water actually passing through the softener and, as a result, the water in a structure using the prior art device would not have truly been xe2x80x9csoft.xe2x80x9d Therefore, it can be seen that there is a need for a more effective seal both around the periphery of the moving orifice plate and between the orifice and the bullet rod.
Further, the requirement of a magnet inside the sensor to interact with the external Reed switches, raised concerns about collection of metallic particles on or near the magnet, possibly preventing the orifice plate from moving as needed. Therefore, it can be seen that there is a need for a means for sensing movement of the orifice plate which does not require a magnet inside the flow path of the sensor.
Prior systems incorporating sensors in multipurpose systems generally assumed that such sensors would be field adjustable. Field adjustability is desirable because it allows an installer to customize the sensor for each installation""s supply pressure and other characteristics as well as for the specific nature of domestic and fire protection demands. However, field adjustability also presents problems because improper installation could present life-threatening danger. Therefore, it may be desired to market a non-field-adjustable version of a multipurpose system to simplify installation, decreasing the chance that such systems will not function properly when needed.
It is therefore an object of the invention to provide an improved apparatus for flow detection and measurement which overcomes the shortcomings of the prior art. It is also an object to provide a method for using the disclosed apparatus in fire protection and/or plumbing systems. The method uses the improved apparatus to overcome one or more of the disadvantages of prior systems.
It is an object of the present invention to provide an improved apparatus for flow detection, and measurement. The apparatus includes a moving orifice plate, a sensor means, a biasing means, and an improved sealing means for preventing flow through the sensor until a specified differential pressure between the sensor""s inlet and outlet ports is reached. The apparatus for flow detection and measurement can incorporate a bypass means for allowing additional flow to pass through the flow measurement device as needed. When water is allowed to flow through the bypass means, an alarm may be enunciated should the flow reach a specified low-flow level. For example, the objects of the apparatus may be accomplished by providing a moving orifice plate with a magnet moving in cooperation therewith. The magnet activates a Reed switch on an external surface of the flow sensor when the moving orifice plate is displaced a sufficient distance by the flow passing through the sensor. When the water demand exceeds that which can flow through the primary path, the moving orifice plate is displaced beyond bullet rod allowing flow through the orifice. Improved means for sealing between the outer periphery of the moving orifice plate and an inner wall of the sensor body and between the orifice and the bullet rod are provided.
The use of a xe2x80x9csteel sensorxe2x80x9d and a non-magnetic ferrous moving orifice plate is also disclosed. No magnet is needed inside of the sensor""s flow path when a steel sensor is used. Rather, the steel sensor is mounted on the outside of the sensor body; when the ferrous moving orifice plate moves to a set point, the steel sensor detects the presence of the moving orifice plate. A small, weak magnet inside the steel sensor is drawn toward the moving orifice plate as it approaches the steel sensor, activating the sensor. Thus, the position of the moving orifice plate can be monitored without the need for a magnet in the flow path.
A system incorporating a pressure regulator on the incoming supply line is disclosed to obviate the need for the sensor to be field-adjustable. Adding a pressure regulator ensures that a uniform supply pressure is applied to the system. However, field installers must still certify that the minimum required supply pressure (preferably at least 60 psi) is available from the supply. If sufficient pressure is not available, the system may not function as intended.
There have thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in this application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. Additional benefits and advantages of the present invention will become apparent in those skilled in the art to which the present invention relates from the subsequent description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientist, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.